Arimoclomol is a heat shock protein amplifier currently under evaluation in the treatment of paediatric lysosomal storage disorders and amyotrophic lateral sclerosis (ALS).
The physical properties of arimoclomol make the drug somewhat difficult to handle. The drug substance is white in appearance, light and fluffy. Arimoclomol is hygroscopic i.e. it absorbs moisture (water molecules) from its surroundings. Arimoclomol has a relatively short plasma half-life (2-4 hours) and multiple daily dosing is currently required.
Arimoclomol is to date administered as powder-filled, coated gelatine capsules (arimoclomol capsules). The arimoclomol capsules are of immediate-release (IR) type.
Arimoclomol has been tested in healthy human volunteers and no maximum tolerated dose has been reached. A total of 261 subjects have been exposed to oral single ascending or repeated doses of arimoclomol ranging from 50 to 800 mg in seven concluded Phase I trials and two concluded Phase II trials, and is found to be safe and well-tolerated.
In the single- and multiple-dose Phase I studies, slight and reversible increases in serum creatinine levels were observed in a number of volunteers but these were not considered to be clinically significant (see e.g. Cudkowicz et al., Muscle & Nerve, July 2008, p. 837-844).